A TCP/IP offload network interface device (NID) receives packets from a plurality of clients and generates, from the socket address of each such packet, a hash value. Each hash value identifies one of a plurality of hash buckets maintained on the NID. In a file server, certain socket address bits of the packets are low entropy bits in that they tend to be the same, regardless of which client sent the packet. Others of the socket address bits are high entropy bits. The hash function employed is such that the hash values resulting from the changing values of the high entropy bits are substantially evenly distributed among the plurality of hash buckets. In a fast-path, the NID uses a first hash function to identify TCBs on the NID. In a slow-path, the NID generates a second hash using a second hash function and a host stack uses the second hash.